311 lines
11 KiB
C#
311 lines
11 KiB
C#
#if FANTASY_NET || !FANTASY_WEBGL
|
||
using System;
|
||
using System.Collections.Generic;
|
||
using System.Linq;
|
||
using System.Numerics;
|
||
using Fantasy.LowLevel;
|
||
#pragma warning disable CS8618 // Non-nullable field must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring as nullable.
|
||
|
||
namespace Fantasy.Helper
|
||
{
|
||
/// <summary>
|
||
/// 随机数操作助手类，提供各种随机数生成和操作方法。
|
||
/// </summary>
|
||
public static partial class RandomHelper
|
||
{
|
||
[ThreadStatic]
|
||
private static Random _random;
|
||
|
||
/// <summary>
|
||
/// 生成一个随机的无符号 64 位整数。
|
||
/// </summary>
|
||
/// <returns>无符号 64 位整数。</returns>
|
||
public static ulong RandUInt64()
|
||
{
|
||
var byte8 = new FixedBytes8().AsSpan();
|
||
var random = _random ??= new Random();
|
||
random.NextBytes(byte8);
|
||
return BitConverter.ToUInt64(byte8);
|
||
}
|
||
|
||
/// <summary>
|
||
/// 生成一个随机的 64 位整数。
|
||
/// </summary>
|
||
/// <returns>64 位整数。</returns>
|
||
public static long RandInt64()
|
||
{
|
||
var byte8 = new FixedBytes8().AsSpan();
|
||
var random = _random ??= new Random();
|
||
random.NextBytes(byte8);
|
||
return BitConverter.ToInt64(byte8);
|
||
}
|
||
|
||
/// <summary>
|
||
/// 生成一个随机的无符号 32 位整数。
|
||
/// </summary>
|
||
/// <returns>无符号 32 位整数。</returns>
|
||
public static uint RandUInt32()
|
||
{
|
||
var random = _random ??= new Random();
|
||
return (uint) random.Next();
|
||
}
|
||
|
||
/// <summary>
|
||
/// 生成一个随机的无符号 16 位整数。
|
||
/// </summary>
|
||
/// <returns>无符号 16 位整数。</returns>
|
||
public static ushort RandUInt16()
|
||
{
|
||
var byte2 = new FixedBytes2().AsSpan();
|
||
var random = _random ??= new Random();
|
||
random.NextBytes(byte2);
|
||
return BitConverter.ToUInt16(byte2);
|
||
}
|
||
|
||
/// <summary>
|
||
/// 在指定范围内生成一个随机整数（包含下限，不包含上限）。
|
||
/// </summary>
|
||
/// <param name="lower">下限。</param>
|
||
/// <param name="upper">上限。</param>
|
||
/// <returns>生成的随机整数。</returns>
|
||
public static int RandomNumber(int lower, int upper)
|
||
{
|
||
var random = _random ??= new Random();
|
||
return random.Next(lower, upper);
|
||
}
|
||
|
||
/// <summary>
|
||
/// 生成一个随机的布尔值。
|
||
/// </summary>
|
||
/// <returns>随机的布尔值。</returns>
|
||
public static bool RandomBool()
|
||
{
|
||
var random = _random ??= new Random();
|
||
return (random.Next() & 1) == 0;
|
||
}
|
||
|
||
/// <summary>
|
||
/// 从数组中随机选择一个元素。
|
||
/// </summary>
|
||
/// <typeparam name="T">数组元素的类型。</typeparam>
|
||
/// <param name="array">要选择的数组。</param>
|
||
/// <returns>随机选择的数组元素。</returns>
|
||
public static T RandomArray<T>(this T[] array)
|
||
{
|
||
return array[RandomNumber(0, array.Count())];
|
||
}
|
||
|
||
/// <summary>
|
||
/// 从列表中随机选择一个元素。
|
||
/// </summary>
|
||
/// <typeparam name="T">列表元素的类型。</typeparam>
|
||
/// <param name="array">要选择的列表。</param>
|
||
/// <returns>随机选择的列表元素。</returns>
|
||
public static T RandomArray<T>(this List<T> array)
|
||
{
|
||
return array[RandomNumber(0, array.Count())];
|
||
}
|
||
|
||
/// <summary>
|
||
/// 打乱列表中元素的顺序。
|
||
/// </summary>
|
||
/// <typeparam name="T">列表元素的类型。</typeparam>
|
||
/// <param name="arr">要打乱顺序的列表。</param>
|
||
public static void BreakRank<T>(List<T> arr)
|
||
{
|
||
if (arr == null || arr.Count < 2)
|
||
{
|
||
return;
|
||
}
|
||
|
||
var random = _random ??= new Random();
|
||
for (var i = 0; i < arr.Count / 2; i++)
|
||
{
|
||
var index = random.Next(0, arr.Count);
|
||
(arr[index], arr[arr.Count - index - 1]) = (arr[arr.Count - index - 1], arr[index]);
|
||
}
|
||
}
|
||
|
||
/// <summary>
|
||
/// 生成一个介于 0 和 1 之间的随机单精度浮点数。
|
||
/// </summary>
|
||
/// <returns>随机单精度浮点数。</returns>
|
||
public static float RandFloat01()
|
||
{
|
||
var random = _random ??= new Random();
|
||
var value = random.NextDouble();
|
||
return (float) value;
|
||
}
|
||
|
||
private static int Rand(int n)
|
||
{
|
||
var rd = new Random();
|
||
// 注意，返回值是左闭右开，所以maxValue要加1
|
||
return rd.Next(1, n + 1);
|
||
}
|
||
|
||
/// <summary>
|
||
/// 根据权重随机选择一个索引。
|
||
/// </summary>
|
||
/// <param name="weights">权重数组，每个元素表示相应索引的权重。</param>
|
||
/// <returns>随机选择的索引值。</returns>
|
||
public static int RandomByWeight(int[] weights)
|
||
{
|
||
var sum = weights.Sum();
|
||
var numberRand = Rand(sum);
|
||
var sumTemp = 0;
|
||
for (var i = 0; i < weights.Length; i++)
|
||
{
|
||
sumTemp += weights[i];
|
||
if (numberRand <= sumTemp)
|
||
{
|
||
return i;
|
||
}
|
||
}
|
||
|
||
return -1;
|
||
}
|
||
|
||
/// <summary>
|
||
/// 根据固定概率随机选择一个索引，即某个数值上限内随机多少次。
|
||
/// </summary>
|
||
/// <param name="args">概率数组，每个元素表示相应索引的概率。</param>
|
||
/// <returns>随机选择的索引值。</returns>
|
||
public static int RandomByFixedProbability(int[] args)
|
||
{
|
||
var random = _random ??= new Random();
|
||
var argCount = args.Length;
|
||
var sum = args.Sum();
|
||
var value = random.NextDouble() * sum;
|
||
while (sum > value)
|
||
{
|
||
sum -= args[argCount - 1];
|
||
argCount--;
|
||
}
|
||
|
||
return argCount;
|
||
}
|
||
|
||
/// <summary>
|
||
/// 返回随机数。
|
||
/// </summary>
|
||
/// <param name="containNegative">是否包含负数。</param>
|
||
/// <returns>返回一个随机的单精度浮点数。</returns>
|
||
public static float NextFloat(bool containNegative = false)
|
||
{
|
||
var random = _random ??= new Random();
|
||
float f;
|
||
var buffer = new FixedBytes4().AsSpan();
|
||
if (containNegative)
|
||
{
|
||
do
|
||
{
|
||
random.NextBytes(buffer);
|
||
f = BitConverter.ToSingle(buffer);
|
||
} while ((f >= float.MinValue && f < float.MaxValue) == false);
|
||
|
||
return f;
|
||
}
|
||
|
||
do
|
||
{
|
||
random.NextBytes(buffer);
|
||
f = BitConverter.ToSingle(buffer);
|
||
} while ((f >= 0 && f < float.MaxValue) == false);
|
||
|
||
return f;
|
||
}
|
||
|
||
/// <summary>
|
||
/// 返回一个小于所指定最大值的非负随机数。
|
||
/// </summary>
|
||
/// <param name="maxValue">要生成的随机数的上限（随机数不能取该上限值）。 maxValue 必须大于或等于零。</param>
|
||
/// <returns>大于等于零且小于 maxValue 的单精度浮点数，即：返回值的范围通常包括零但不包括 maxValue。 不过，如果 maxValue 等于零，则返回 maxValue。</returns>
|
||
public static float NextFloat(float maxValue)
|
||
{
|
||
if (maxValue.Equals(0))
|
||
{
|
||
return maxValue;
|
||
}
|
||
|
||
if (maxValue < 0)
|
||
{
|
||
throw new ArgumentOutOfRangeException("“maxValue”必须大于 0。", "maxValue");
|
||
}
|
||
|
||
var random = _random ??= new Random();
|
||
float f;
|
||
var buffer = new FixedBytes4().AsSpan();
|
||
|
||
do
|
||
{
|
||
random.NextBytes(buffer);
|
||
f = BitConverter.ToSingle(buffer);
|
||
} while ((f >= 0 && f < maxValue) == false);
|
||
|
||
return f;
|
||
}
|
||
|
||
/// <summary>
|
||
/// 返回一个指定范围内的随机数。
|
||
/// </summary>
|
||
/// <param name="minValue">返回的随机数的下界（随机数可取该下界值）。</param>
|
||
/// <param name="maxValue">返回的随机数的上界（随机数不能取该上界值）。 maxValue 必须大于或等于 minValue。</param>
|
||
/// <returns>一个大于等于 minValue 且小于 maxValue 的单精度浮点数，即：返回的值范围包括 minValue 但不包括 maxValue。 如果 minValue 等于 maxValue，则返回 minValue。</returns>
|
||
public static float NextFloat(float minValue, float maxValue)
|
||
{
|
||
if (minValue.Equals(maxValue))
|
||
{
|
||
return minValue;
|
||
}
|
||
|
||
if (minValue > maxValue)
|
||
{
|
||
throw new ArgumentOutOfRangeException("“minValue”不能大于 maxValue。", "minValue");
|
||
}
|
||
|
||
var random = _random ??= new Random();
|
||
var buffer = new FixedBytes4().AsSpan();
|
||
float f;
|
||
|
||
do
|
||
{
|
||
random.NextBytes(buffer);
|
||
f = BitConverter.ToSingle(buffer);
|
||
} while ((f >= minValue && f < maxValue) == false);
|
||
|
||
return f;
|
||
}
|
||
|
||
/// <summary>
|
||
/// 在指定的矩形区域内随机生成一个二维向量位置。
|
||
/// </summary>
|
||
/// <param name="minX">X轴最小值。</param>
|
||
/// <param name="maxX">X轴最大值。</param>
|
||
/// <param name="minY">Y轴最小值。</param>
|
||
/// <param name="maxY">Y轴最大值。</param>
|
||
/// <returns>随机生成的二维向量位置。</returns>
|
||
public static Vector2 NextVector2(float minX, float maxX, float minY, float maxY)
|
||
{
|
||
return new Vector2(NextFloat(minX, maxX), NextFloat(minY, maxY));
|
||
}
|
||
|
||
/// <summary>
|
||
/// 生成指定长度的随机数字代码。
|
||
/// </summary>
|
||
/// <param name="len">数字代码的长度。</param>
|
||
/// <returns>生成的随机数字代码。</returns>
|
||
public static string RandomNumberCode(int len = 6)
|
||
{
|
||
int num = 0;
|
||
for (int i = 0; i < len; i++)
|
||
{
|
||
int number = RandomNumber(0, 10);
|
||
num = num * 10 + number;
|
||
}
|
||
|
||
return num.ToString();
|
||
}
|
||
}
|
||
}
|
||
#endif |